1. Technical Field
The invention relates to an optical lens structure. Particularly, the invention relates to a wafer level optical lens structure.
2. Related Art
Along with a trend of module miniaturization and low price of electronic products, a wafer level module (WLM) technique draws attention. The WLM technique is mainly to use a wafer level fabrication technique to miniaturize a volume of the electronic product and decrease the cost thereof. For example, when the aforementioned technique is applied to fabricate wafer level optical (WLO) lens modules, the WLO lens modules may have smaller volume compares with that of a conventional lens module, so that the WLO lens modules can be applied to camera modules of, for example, mobile phones.
Along with increasing demand on optical quality of the WLO lens module, a structure of the WLO lens module gradually becomes complicated, and the WLO lens module has to include multiple layers of different material structures to satisfy the market demand. However, due to different physical characteristics of different materials, a stress effect between different layers of material is liable to cause defects in the WLO lens modules during a fabrication process, which decreases a product yield of the WLO lens modules.